Craysh Cambarus bartoni Turn over a rock in almost any North Carolina stream in summer - PDF document

Cray“sh Cambarus bartoniTurn over a rock in almost any North Carolina stream in summer, and chancesare a crayÞsh will dart backwards away from you or even defend the rockwith its claws pointed at you. There are at least 40 different species of thiscommon freshwater crustacean that live in Tar Heel streams, ponds, androws from the mountains to the coast. Many of these species are foundnowhere else on earth. Description CrayÞshes look like miniature lobsters, with a front pair of strong pinchingclaws, an armored body, and a broad tail. Like lobsters, crayÞshes have 3 mainbody parts: a head, thorax and abdomen and a hard exoskeleton that protectstheir soft tissues and organs. The front part of the body is rigid, but the backpart, the abdomen or tail, has movable segments. In the head region, 2 pairsof antennae and tiny eyes aid the crayÞsh in sensing its surroundings. In thethorax, crayÞshes have 5 legs on each side (of their body) and soft featherygills that are used for respiration. The Þrst pair of legs are large claws or pin-cers, and these help the crayÞshes catch and hold their prey. The next 4 pairsof legs are walking legsÑthe Þrst 2 of these pairs are small pincers used tohandle food. Under the tail and after the last pair of walking legs, there aresmaller and thinner leg-like appendages called swimmerets, that aid in swim-ming, carrying eggs, and holding young crayÞsh. Depending on the species,the crayÞshesÕ color ranges from crimson red to cobalt blue. Some can bepink, brown, greenish black or even aquamarine. History and Status Our biologists discover and describe new species of crayÞsh every year andalso document the spread of exotic crayÞshes in the state. As more surveysare completed, biologists continue to document the range expansion and alsothe contraction of some of North CarolinaÕs crayÞshes. Habitat and Habits CrayÞshes inhabit streams, ponds, lakes and swamps throughout North Car olina. Stream dwellers prefer fast-moving and highly oxygenated rivers andstreams of the Mountains and Piedmont regions. In slower streams, as in theCoastal Plain, crayÞshes hide under rocks and logs for protection. CrayÞshescan also be found in ponds, lakes, and in standing water in roadside ditches.Þsh burrow in the ground and can dig branching tunnels up to15 ft. deep in muddy wetlands. Most burrows average about 2 or 3 ft. deep Cray“shNorth Carolina Wildlife ProÞles You get a line and Ill get a pole„Well go “shing in a crawdad hole...Ž Some cray“sh are generalists and occurthroughout much of North Carolina, butmost are restricted to smaller geographicareas. The Greensboro burrowing cray“sh,, are only found aroundthe Greensboro area, and the North Car -olina spiny cray“sh, Orconectes carolinensisare only found in the Tar and Neuse RiverBasins in the coastal plain.In North Carolina, the cray“sh can be and can be found a good distance away from standing water. Burrowing cray Þshes, found mostly in the Coastal Plain and eastern North Carolina, often pitchup clay ÒchimneysÓ as they dig.CrayÞshes become most active at nightfall or at daybreak, and emerge fromtheir hiding places to feed. These tough crustaceans eat primarily aquatic vegeta-tion, but they may also eat small, live ordead animals such as worms, snails, tad poles and Þsh. CrayÞshes often becomeprey to other animals such as bullfrogs,turtles, bass, raccoons, wading birds andhawks. But crayÞsh are Þghters. Their bestdefense is a powerful tail, which propels theÞsh backward. If they lose a claw orleg in battle, a new one grows in its place.Most crayÞsh species in North Carolina produce their young in early spring,when food and rain are plentiful. A few species breed in winter. To mate, themale crayÞsh grasps the female and turns her over so their ventral sides aretogether. Then the male passes sperm through his Þrst pair of swimmerets, calledthe gonopod, to the female. When fertilized, hundreds of tiny eggs attach to thefemaleÕs swimmerets with a sticky discharge called glair. When the female crayÞshhas the fertilized eggs attached it is said that she is in berry. Larger females typi-callyproduce more eggs. Unlike many other crustaceans, crayÞshes do not go through a larval stagebut molt about 6 times in the Þrst 7 to 8 months of life. Molting, or sheddingof the shell is necessary because crayÞshes outgrow their armor. Theycontinueto molt at a slower rate for the rest of their lives. When they molt, the old skele-ton falls away and the soft-shelled crayÞshes grow quickly as they take in largeamounts of water. Unprotected, they hide after molting and are less aggres until the new skeleton hardens in several days. CrayÞshes thrivein unpollutedwater and their numbers are a good sign of a good ecology. People Interactions In addition to their ecological importance, crayÞshes are also valued economically.Larger Òcrawdads,Ó such as the red swamp crayÞsh, are considered a delicacy ofCajun cooking. Crawdads are also used as Þshing bait, and this has led to someaccidental introductions of non-native crayÞsh into new areas. Non-native cray-Þshes hurt our ecosystem by competing with native Tarheel species and destroy-ing aquatic plants that provide food and shelter for native animals. DO NOT release crayÞshes into North Carolina waterways!!!Once they arehere, they are impossible to eradicate! Here is a tip for anyone unfortunateenough to get on the wrong end of a crayÞsh. They have a sharp pinch butpinch only as a last ditch effort in self defense. If given the chance to ßee,they will. So if you ever Þnd yourself with a crayÞsh latched on to you, juststick the affected part of your anatomy back into the water where the crayÞshwill feel safer and swim away. This technique also works with snapping turtles. Wild Facts Class: CrustaceaOrder: Decapoda ten-leggedŽAverage SizeAbout 3 in. in lengthFeed primarily on aquatic vegetation butalso eat worms, snails, tadpoles and othersmall live or dead creatures.Most produce young in spring. Femalepro duces hundreds of eggs; about 85%hatch. Number of broods varies. Scien tistsare not sure how long it takes for the eggsto hatch, but they estimate a month ormore. When the eggs do hatch, tiny, trans-parent versions of adult cray“sh emerge,in. long.YoungYoung cling to the female through threemolts, until they reach a size of aboutin. Cray“sh do not go through a larval stage.About 3 to 5 years. Cray“shWildlife ProÞlesÑNorth Carolina Wildlife Resources Commission ReferencesElliott, Alfred M. (3rd ed., Appleton-Century-Crofts, 1963). Kondo, Herbert, ed. The Illustrated Encyclopedia of the Animal Kingdom(Danbury Press, 1972).Pßieger, William L. 1996 . The CrayÞshes of Missouri. Missouri Department of Conservation. Pitre, Glen. The CrawÞsh Book(University Press of Mississippi, 1993). CreditsWritten by Sarah Friday. Updated by Robert Nichols, North Carolina Wildlife Resources Commission.Illustrated by J.T. Newman and Consie Powell. Photos by North Carolina Wildlife Resources Commission.Produced by the Division of Conservation Education, Cay CrossÐEditor, Carla OsborneÐDesigner. The N.C. Wildlife Resources Commission is an Equal Opportunity Employer, and all wildlife programs are administered for the beneÞt of all North Carolina citizens without prejudicetoward age, sex, race, religion or national origin. Violations of this pledge may be reported to the Equal Employment OfÞcer, N.C. Wildlife Resources Commission, 1751 Varsity Dr.,Raleigh, N.C. 27606. (919) 707-0101. Cray“shWildlife ProÞlesÑNorth Carolina Wildlife Resources CommissionQ&A .Where can you go for more information about cray“sh? http://www.ncwildlife.org/fs_index_07_conservation.htm, then click on the subtopic SPECIES, then click onNorth Carolina CrayÞshes: Life at the BottomAlso check out the CrayÞshes of North Carolina Web site:http://www.ncwildlife.org/pg07_WildlifeSpeciesCon/nccrayÞshes/index.html.Which direction do cray“shes swim and how do they do it? They propel themselves backward with their tail..What does it mean for a cray“sh to molt? What do they lose? The old outer skeleton falls away..What are the cray“shs large claws used for? Large claws are used to catch and hold food..What happens when a cray“sh loses its claw? It grows another claw.Note: ÔcrayÞshÕ refers to a single species or an individual specimen, whereas ÔcrayÞshesÕ refer to many species. Links To see a video on the crayfish (also known as ÒcrawfishÓ), go to http://dsc.discovery.com/videos/dirty-job-crawfish-catcher.html The circle of life... Crayfish are considered a delicacy to eat and, in addi-tion to their ecological importance, cray fishes arevalued economically. Larger crawdadsŽ such as thered swamp crayfish, are an important part of Cajuncooking. Crayfish are also part of the estuarine food-chain and become prey for other animals. Bullfrogs,turtles and otters enjoy a crunchy cray“sh lunch.